The seat adjuster arrangement of this invention is similar to that shown in U.S. patent application Ser. No. 383,471, Vertical Seat Adjuster for Vehicle Seats, Richard W. A. Rees, filed June 1, 1982, and assigned to the assignee of this invention. Both seat adjuster arrangements include inboard and outboard seat adjuster mechanisms of different hand. Each mechanism obtains vertical adjustment of the front or rear portion of the seat through rotation of respective spaced front and rear levers which are pivoted both to a seat support bracket supporting the seat and to a relatively fixed respective vehicle pivotal connection. Conjoint rotation of the front and rear pairs of levers of the inboard and outboard mechanisms about their relatively fixed vehicle pivotal connections is assured by transfer tubes interconnecting the seat support bracket pivots of the levers. Such rotation raises and lowers the respective front and rear portions of the seat.
In the seat adjuster arrangement of this invention, a manually operable screwjack mechanism is coupled to the transfer tube interconnecting the rear levers to rotate such levers. The screwjack mechanism holds the rear portion of the seat in a vertically adjusted position. The front portion of the seat is vertically adjusted by the seat occupant shifting weight to rotate the front pair of levers about their relatively fixed vehicle pivotal connections.
In order to lock the front portion of the seat in a vertically adjusted position, the seat support brackets are each provided with a lock plate which is slidably mounted thereon for movement between engaged and released positions relative to a respective front vehicle pivotal connection which functions as a detent means for the lock plate. Each lock plate includes a series of alternating notches and teeth which respectively function as detent engaging means and detent abutting means. Each notch defines a vertically adjusted position of the seat. The notches and teeth of one lock plate are offset with respect to those of the other lock plate so that each notch of one lock plate corresponds to a tooth of the other lock plate. Thus, when a notch of one lock plate engages a respective detent means, a tooth of the other lock plate abuts a respective detent means whereby one lock plate is always engaged and the other lock plate is always released in a vertically adjusted position of the seat. However, the seat is locked in each vertically adjusted position since the front levers are coupled together for conjoint rotation by the front transfer tube. By providing alternating teeth and abutments which are offset with respect to each other, a greater number of vertically adjusted positions can be obtained than if the notches and teeth were aligned with respect to each other.
The primary feature of this invention is that is provides an improved seat adjuster arrangement for vehicle seats which includes like mechanisms having conjointly adjustable seat support brackets for supporting the seat and provided with respective locking means alternately engageable with respective detent means to lock the brackets in an adjusted position. Another feature is that each locking means is movable between engaged and released positions relative to a respective detent means, with one of the locking means being located in an engaged position with respect to its detent means and the other locking means being located in a released position with respect to its detent means in each adjusted position of the seat. A further feature is that the detent means are provided by relatively fixed vehicle pivotal connections of levers which are pivotally connected to the seat support brackets and are conjointly rotatable to adjust the brackets. Yet another feature is that the locking means includes a locking plate mounted to each bracket for movement between engaged and released positions, each locking plate having a series of alternating notches and teeth, the engagement of a notch with a respective relatively fixed pivotal connection locking a plate and the brackets in locked position and the abutment of a tooth with a relatively fixed pivotal connection locating a respective locking plate in released position. Yet a further feature is that a notch of one locking plate corresponds to an abutment of the other locking plate whereby the notches and abutments are laterally offset with respect to each other and the number of adjusted positions of the seat obtainable is equal to the number of notches and greater than if the notches were aligned with each other.